Syringe assembly



Feb. 19, 1952 M. L. LOCKHART 2,586,

SYRINGE ASSEMBLY Filed April 4, 1950 IN V EN TOR.

mrmavEXs Patented Feb. 19, 1952 UNITED STATES ip rrsrrr OFFICE IMarshall L. Lockhart, Rutherford, N. J.

Application April 4, 1950, Serial No. 153,793

This invention relates to a structurally and functionally improvedsyringe assembly by means of which an aspirating function may beaccomplished in addition to the usual hypodermic injection.

The present application is a continuation-inpart of my prior applicationfor United States Letters Patent, Serial No. 658,670 entitled Closureand filed in the Patent Oflice on April l, 1946, now Patent No.2,556,331, dated June 12,

Among the objects of the present invention are those of providing adesign which will be relatively simple and capable of being produced bymeans of automatic machinery and methods and which will includerelatively few parts, of rugged construction, operating with freedomfrom all difiiculties over a, long period of time.

With these and other objects in mind, reference is had to the attachedsheet of drawings illustrating one practical embodiment of the drawing,and in which Fig. 1 is a sectional side view of the novel assembly andillustrating the ampule in process of association with the holder;

Fig. 2 is a similar view but showing the parts operatively coupled; and

Fig. 3 is a transverse sectional view taken along the lines 33 and inthe direction of the arrows as indicated in Fig. 2.

In these views, the numeral 5 indicates a holder conveniently formed ofplastic and which mounts a double ended needle 6. The needle isencircled within the holder by a tubular thrust portion I. The bore ofthe latter is flared. The inner needle end extends beyond the inner endof that portion. It is to be understood that the holder as shown ismerely intended for illustration rather than limiting purposes and thatthe invention might be incorporated in an assembly employing a holder ofa different design.

The reference numeral 8 indicates an ampule preferably formed of glassand having oppositely facing compartments divided from each other by apartition 9. The outer ends of these compartments are closed by pistontype stoppers 10. It is apparent that as the inner end of the thrustportion 1 is brought into contact with the outer face of the stopper theinner end of the needle 6 will have penetrated the diaphragm of thestopper. This will establish communication between the needle bore andthe interior of the ampule compartment. Continued inward pressure of theampule will cause the stopper to ride inwardly within the ampule boreand function 5 Claims. (01. 128-226) as a piston to express themedicament through the bore of the cannula. This operation may becontinued until all medicament has been exhausted.

Where a physician desires to ascertain whether the epidermis=penetratingend of the needle is lodged in a vein it is necessary that he aspiratein order to create a condition of pressure such that a drop or so ofblood may discharge from the inner end of the cannula. Such a result maybe achieved by the present construction in that the stopper is furnishedwith a forward, tubular and tapered extension II which has a diametersuch that it may be accommodated within the flared outer end of the boreof the thrust portion. The bore of this extension defines a space suchthat the body of the needle may pass therethrough. The flared bore ofthe thrust portion is defined by a face as indicated at l2. Therefore,as the faces of the extension and thrust portion are forced intocontact, a wedge fit will be established.

The degree of frictional contact will be such that a physician may movethe ampule rearward- 1y without disturbing the relationship of thestopper and thrust portion. Therefore the stopper will move outwardlywith respect to the ampule bore. This will reduce the pressure withinthe ampule compartment and may even create a condition of subatmosphericpressure. In any event, a pressure differential will be brought intobeing which will allow the physician to determine Whether or not theouter end of the needle is lodged in a vein.

Thus, among others, the several objects of the invention as specificallyaforenoted are achieved. Obviously numerous changes in construction andrearrangement of the parts might be resorted to without departing fromthe spirit of the invention as defined by the claims.

I claim:

l. A syringe assembly including in combination a tubular holder, athrust portion forming a part of said holder and extending within thebore thereof, an ampule, a piston stopper closing the end of saidampule, an extension forming a part of said stopper and projectingtowards said thrust portion and said thrust portion being formed with abore to receive and frictionally engage the surfaces to said extension.

2. A syringe assembly including in combination a tubular holder, athrust portion forming a part of said holder and extending within thebore thereof, an ampule, a piston stopper closing the end of saidampule, an extension forming a part of said stopper and projectingtowards said thrust portion, said thrust portion being formed with abore to receive and frictionally engage the surfaces of said extension,and the surfaces of said bore and extension being tapered to provide awedge fit.

3. A syringe assembly including in combination a holder formed with abore, a thrust portion extending rearwardly within said bore, a needleen circled by .said thrust portion and extending beyond the same andsaid thrust portion defining a tapered recess to receive an extendedportion forming a part of an ampule-stopper to be engaged by said thrustportion and penetrated by said needle.

4. A syringe assembly including in combination a holder formed with abore, a thrust portion extending rearwardly within said bore, saidthrust portion defining a tapered recess, a stopper and an extended pantforming a portion of said stopper and proiectible into'wedgingiengagement with the surfaces of said recess, such that saidstopper will move withrsaid thrust portionas the latter tends to pullaway from said stopper-whereby said stopper may function to causeaspiration within said assembly.

5. A syringe assembly including in combination a holder formed with abore, a thrust portion extending rearwardly within said bore, saidthrust portion defining a tapered recess, a stopper and an extended partforming a portion of said stopper and projectible into a wedgingengagement with the surfaces of said recess, the outer surfaces of saidextended part being tapered.

MARSHALL L. LOCKHART.

REFERENCES CITED The following references are of record in the file iofthis patent:

UNITED STATES PATENTS 20 Number Name Date 1,237,761 Dwyer -v Aug. :21,1917 1,=8l'7;003 Hein Aug. 4, 1931 2,000,434 Baudouin et a1 May 7, 1935

